The long term goal of this research is to develop a highly sensitive non-radioactive detection method for DNA hybrids which will be useful with clinical samples. DNA hybridization probes are proving to be useful for the detection of specific bacteria and viruses as well as for the detection of inherited or acquired (such as oncogenes) genetic alterations. In order to fully utilize the potential of such probes in a clinical setting highly sensitive non-radioactive detection method is needed. Currently radioactive detection is the most sensitive; however, enzymes with a high turn-over-number that can be coupled to the generation of light can give even greater sensitivity. We propose to develop such a sensitive method by coupling the production of NADH by glucose-6-phosphate dehydrogenase to bacterial luciferase using FMN+:NADH oxidoreductase. Since appropriate instrumentation can detect-light with extreme sensitivity, such a light generating system can be more sensitive than current colorimetric methods or radiolabeling.